Three‐Component Synthesis of 2‐Substituted Thiobenzoazoles Using Tetramethyl Thiuram Monosulfide (TMTM) as Thiocarbonyl Surrogate
作者:Xi Wang、Chun‐Yan Wu、Yue‐Sheng Li、Zhi‐Bing Dong
DOI:10.1002/ejoc.202001214
日期:2020.11.22
A metal‐free synthesis of 2‐benzyl/allyl‐substituted thiobenzoazoles was developed starting from tetramethyl thiuram monosulfide (TMTM) which served as thiocarbonyl surrogate. By using 2‐aminophenols (or 2‐aminothiophenols, or 1,2‐phenylenediamines) and TMTM as starting materials, 2‐mercaptobenzoazoles could be synthesized efficiently, and the subsequent C–S bond formation with allyl/benzyl halides
A transition-metal-free protocol for the one-pot synthesis of 2-benzyl/2-allyl-substituted thiobenzoazoles in water was developed. The cyclization of 2-aminothiophenols, 2-aminophenols, and 1,2-phenylenediamines with tetramethylthiuram disulfide (TMTD) gave mercapto benzoheterocycles, and the subsequent C-S coupling with benzyl or allyl halides furnished the desired products in good to excellent yields. This method features transition-metal-free conditions with water as a solvent, an easy performance, mild reaction conditions, a wide substrate scope, and good to excellent yields, thus paving an efficient and useful way to establish a library of potentially active drug molecules.